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Quark-Gluon Plasma (QGP)
03/31/2017 Rongrong Ma (BNL), Moriond 2
• Lattice-QCD predicts a phase transition from confined hadrons to the Quark Gluon Plasma (QGP) where quarks and gluons are deconfined. – εc ~ 0.6 GeV/fm3; Tc ~ 150 MeV
2015 Long Range Plan
Quark-Gluon Plasma (QGP)
03/31/2017 Rongrong Ma (BNL), Moriond 3
• Have existed in early universe: t ~ 10-6s
• Lattice-QCD predicts a phase transition from confined hadrons to the Quark Gluon Plasma (QGP) where quarks and gluons are deconfined. – εc ~ 0.6 GeV/fm3; Tc ~ 150 MeV
2015 Long Range Plan
Probe QGP with Heavy Flavor
03/31/2017 Rongrong Ma (BNL), Moriond 4
• HEAVY: mc,b >> TQGP, ΛQCD – Produced in high-Q2 scatterings à calculable in pQCD; scales with binary
nucleon-nucleon collisions in heavy-ion collisions – Produced at early stage à imprint the entire evolution history of QGP
Probe QGP with Heavy Flavor
03/31/2017 Rongrong Ma (BNL), Moriond 5
• HEAVY: mc,b >> TQGP, ΛQCD – Produced in high-Q2 scatterings à calculable in pQCD; scales with binary
nucleon-nucleon collisions in heavy-ion collisions – Produced at early stage à imprint the entire evolution history of QGP
• Open heavy flavor (Qq, Qqq) – Radiative+collisional energy loss à transport coefficient
– Collective behavior à spatial diffusion coefficient – Hadronization mechanism, e.g. coalescence
ΔEg > ΔEu ,d ,s > ΔEc > ΔEb
“Brownian” motion
(q, e)
Probe QGP with Heavy Flavor
03/31/2017 Rongrong Ma (BNL), Moriond 6
• HEAVY: mc,b >> TQGP, ΛQCD – Produced in high-Q2 scatterings à calculable in pQCD; scales with binary
nucleon-nucleon collisions in heavy-ion collisions – Produced at early stage à imprint the entire evolution history of QGP
• Open heavy flavor (Qq, Qqq) – Radiative+collisional energy loss à transport coefficient
– Collective behavior à spatial diffusion coefficient – Hadronization mechanism, e.g. coalescence
ΔEg > ΔEu ,d ,s > ΔEc > ΔEb
“Brownian” motion
(q, e)
• Quarkonium (QQ) – Dissociation: QQ potential color-screened in the medium à
direct evidence of QGP formation • However, deconfined quarks and anti-quarks can recombine
– Sequential melting: different quarkonia dissociate at different temperatures à constrain medium temperature
The Solenoid Tracker At RHIC
Ø HFT (2014-2016): measure track points • Inner pixel layers (MAPS): high
resolution; low material budget
Ø TPC: measure momentum and energy loss
Ø TOF: measure particles’ flight time to enhance PID at low pT
Ø BEMC: trigger on and identify high-pT electrons
Ø MTD (2013-present): trigger on and identify muons • |η| < 0.5, φ ~ 45% • Less bremsstrahlung
03/31/2017 Rongrong Ma (BNL), Moriond
Muon Telescope Detector
Time Of Flight
• Large acceptance: |η| < 1, 0 < φ < 2π
Barrel ElectroMagne9c Calorimeter
7
Time Projec9on Chamber
Heavy Flavor Tracker
(GeV/c)TTransverse Momentum p0 1 2 3 4 5 6 7 8
AAR
00.20.40.60.8
11.21.41.61.8 Au+Au 200GeV, 0-10%
20140D2010/110D
π (0-12%)
STAR Preliminary
p+p uncert.
03/31/2017 Rongrong Ma (BNL), Moriond 8
STAR: PRL 113 (2014) 142301 STAR: PLB 655 (2007) 2014
• Strong suppression of D0 meson at high pT à substantial energy loss of charm quarks due to strong interactions with the medium
• RAA(D0) ~ RAA(π) above 3 GeV/c: spectrum shape & fragmentation play an important role
B/D Energy Loss
Djordjevic et al. PRC 90 (2014) 034910
RAA =σ inel
pp
Ncoll
d 2NAA / dydpTd 2σ pp / dydpT
(GeV/c)TTransverse Momentum p0 1 2 3 4 5 6 7 8
AAR
00.20.40.60.8
11.21.41.61.8 Au+Au 200GeV, 0-10%
20140D2010/110D
π (0-12%)
STAR Preliminary
p+p uncert.
03/31/2017 Rongrong Ma (BNL), Moriond 9
STAR: PRL 113 (2014) 142301 STAR: PLB 655 (2007) 2014
• Strong suppression of D0 meson at high pT à substantial energy loss of charm quarks due to strong interactions with the medium
• RAA(D0) ~ RAA(π) above 3 GeV/c: spectrum shape & fragmentation play an important role
)c (GeV/T
p1 2 3 4 5 6 7 8
AA
R
1
= 200 GeVNNsAu+Au 0-80%
STAR Preliminary
0.2
e→Be→D
e→BDUKE : e→DDUKE :
uncertaintye→B+DAAR
DUKE: PRC 92 (2015) 024907
• RAA(Bàe) > RAA(Dàe) à consistent with mass hierarchy
B/D Energy Loss
Djordjevic et al. PRC 90 (2014) 034910
RAA =σ inel
pp
Ncoll
d 2NAA / dydpTd 2σ pp / dydpT
03/31/2017 Rongrong Ma (BNL), Moriond 10
STAR: arXiv: 1701.06060
• Large non-zero D0 v2 and v3 à strong collective behavior • Both v2 and v3 follow the empirical mT scaling as light hadrons à
charm quarks may have acquired similar flow as light quarks
D0 Anisotropic Flow
) 2 (GeV/cq) / n0 - mT
(m0 0.5 1 1.5 2 2.5
q /
n2
Anis
otro
py P
aram
eter
, v
0
0.05
0.1
0.150D-Ξ
Λ
SK
STAR Au+Au @ 200 GeV10-40%
b)
)2)/NCQ (GeV/c0-mT
(m
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6
3/2
/NC
Q3v
0.01−
0
0.01
0.02
0.03
0.04
0.05
0.06
STAR Preliminary
Au+Au 200 GeV 0-80%0D
p+K
+πφΛ
v2 v3
03/31/2017 Rongrong Ma (BNL), Moriond 11
Compare D0 v2 with Models
SUBATECH: pQCD + hard thermal loop P. B. Gossiaux, J. Aichelin, T. Gousset, and V. Guiho, Strangeness in quark matter TAMU: T-matrix, non-perturbative, internal energy potential M. He, R. J. Fries, and R. Rapp, PRC86, 014903 (2012) Duke: free constant Ds, fit to LHC high pT RAA S. Cao, G.-Y. Qin, and S. A. Bass, PRC88, 044907 (2013) hydro: A 3D viscous hydrodynamic model L.-G. Pang, Y. Hatta, X.-N. Wang, and B.-W. Xiao,PRD91, 074027 (2015) PHSD: Parton-Hadron-String Dynamics, a transport model H. Berrehrah et al. PRC90 (2014) 051901 LBT: A Linearized Boltzmann Transport model S. Cao, T. Luo, G.-Y. Qin, and X.-N. Wang, PRC94, 014909 (2016)
(GeV/c)T
p0 1 2 3 4 5 6 7
2An
isot
ropy
Par
amet
er, v
0
0.1
0.2
0STAR DSUBATECHTAMU c-quark diff.TAMU no c-quark diff.
=7sTDπDuke - 2LBTPHSD3D viscous hydro
STAR Au+Au @ 200 GeV0-80%
• 3D hydro model: agrees with data quite well à fully thermalized • Dynamic models are also consistent with data • Charm quark diffusion is clearly needed • Diffusion coefficient: Ds×2πT ~ 2-12 within Tc-2Tc
STAR: arXiv: 1701.06060
(GeV/c)T
p0 1 2 3 4 5 6 7 8
0/D sD
0
0.2
0.4
0.6
0.8
1Au+Au @ 200 GeVSTAR Preliminary
0-10%10-40%ee/pp/ep averagePYTHIA(ver. 6.4)TAMU(b=7.24fm)
03/31/2017 Rongrong Ma (BNL), Moriond 12
ee/pp/ep average: M. Lisovyi, et al. EPJ C 76 (2016) 397 TAMU: H. Min et al. PRL 110 (2013) 112301
• Ds/D0: larger than fragmentation baseline and PYTHIA à coalescence • TAMU model (10-40%) under-predicts the enhancement around 3 GeV/c
– For TAMU model, even harder to get high-pT enhancement with coalescence
Charm-strange Hadron Enhancement
(GeV/c)T
p0 1 2 3 4 5 6 7 8
0/D sD
0
0.2
0.4
0.6
0.8
1Au+Au @ 200 GeVSTAR Preliminary
0-10%10-40%ee/pp/ep averagePYTHIA(ver. 6.4)TAMU(b=7.24fm)
03/31/2017 Rongrong Ma (BNL), Moriond 13
ee/pp/ep average: M. Lisovyi, et al. EPJ C 76 (2016) 397 TAMU: H. Min et al. PRL 110 (2013) 112301
• Ds/D0: larger than fragmentation baseline and PYTHIA à coalescence • TAMU model (10-40%) under-predicts the enhancement around 3 GeV/c
– For TAMU model, even harder to get high-pT enhancement with coalescence
[GeV/c]T
p0 1 2 3 4 5 6 7 8
Rat
io
0
0.2
0.4
0.6
0.8
1Au+Au @ 200 GeVSTAR Preliminary
, 0-10%0/D+sD
, 10-40%0/D+sD
, 10-40%π/sK
STAR: PRL 108 (2012) 72301 STAR: PRL 97 (2006) 152301
• Charm vs. light flavor: similar enhancement above 3.5 GeV/c, but smaller within 2.5-3.5 GeV/c
Charm-strange Hadron Enhancement
03/31/2017 Rongrong Ma (BNL), Moriond 14
Λc in Heavy-ion Collisions
)2 (GeV/cπpKM2.1 2.2 2.3 2.4 2.5
)2C
ount
s/(1
0 M
eV/c
20
40
60
80
100
120
-π+Kp + +π-pKwrong-sign
Au+Au @ 200GeV 10-60%
<6.0 GeV/cT
3.0<p
STAR Preliminary
21±) = 108 cΛ#(
• First ever Λc signal reconstructed in heavy-ion collisions • 5.4σ significance
(GeV/c)T
Transverse Momentum p
0 1 2 3 4 5 6
Bary
on-to
-Mes
on R
atio
s
1−10
1
)-π++π()p(p+
60-80%
0-12%
(GeV/c)T
Transverse Momentum p
0 1 2 3 4 5 6
2An
isot
ropy
Par
amet
er v
1−10
1
S02K)Λ+Λ(
60-80%
0-5%
(GeV/c)T
Transverse Momentum p
0 1 2 3 4 5 6
2An
isot
ropy
Par
amet
er v
1−10
1
)0D+0(D
)cΛ+cΛ(
10-60%
PYTHIA
/D)cΛGreco (
Ko: three-quark
0-5%
Ko: di-quark
SHM
STAR Preliminary
Au+Au @ 200GeVBa
ryon
/Mes
on R
atio
s
Transverse Momentum (GeV/c)
03/31/2017 Rongrong Ma (BNL), Moriond 15
Ko: Y. O
h, et al. PRC 79 (2009) 044905
Greco: S. G
hosh, et al. PRD 90 (2014) 054018
SHM
: Y. O
h, et al. PRC 79 (2009) 044905
I. Kuznetsova and J. Rafelski,, EPJ C
51 (2007) 113 A. Andronic,, et al. PLB
659 (2008) 149
• Enhancement of Λc/D0 ratio relative to PYTHIA prediction Ø STAR: 1.3 ± 0.3 (stat) ± 0.4 (sys); PYTHIA: 0.1-0.15
• Ko model (0-5%) including coalescence and thermalized charm quark is consistent with data
• Magnitude of the enhancement is similar to that for light hadrons
Λc Enhancement in Heavy-ion Collisions
partN0 50 100 150 200 250 300 350
pA,A
A R
ψJ/
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2, |y| < 0.5-µ+µ→ψSTAR J/
> 0 GeV/cT
Au+Au @ 200 GeV, p > 5 GeV/c
TAu+Au @ 200 GeV, p
> 1 GeV/cT
p+Au @ 200 GeV, p > 5 GeV/c
Tp+Au @ 200 GeV, p
uncertaintycollN
STAR preliminary
J/ψ RAA vs. Centrality
• Central collisions: significant suppression for pT > 0 GeV/c and pT > 5 GeV/c à interplay of dissociation, regeneration, formation time effect, etc.
• Peripheral collisions: RAA of J/ψ for pT > 0 GeV/c is less than 1à consistent with cold nuclear matter (CNM) effects
03/31/2017 Rongrong Ma (BNL), Moriond 16
Au Au Au Au
partN0 50 100 150 200 250 300 350
AA
Rψ
J/
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
uncertaintycollSTAR N
STAR preliminary > 0 GeV/cψT,J/
p, |y| < 0.5-µ+µ→ψ = 200 GeV, J/NNsSTAR: Au+Au,
, |y| < 0.35-e+e→ψ = 200 GeV, J/NNsPHENIX: Au+Au, , |y| < 0.8-e+e→ψ = 2.76 TeV, J/NNsALICE: Pb+Pb,
03/31/2017 Rongrong Ma (BNL), Moriond 17
ALICE : PLB 734 (2014) 314 PHENIX : PRL 98 (2007) 232301 pT
> 0 GeV/c
• pT > 0 GeV/c: more suppressed at RHIC in central events à smaller regeneration contribution due to lower charm cross-section
J/ψ RAA: RHIC vs. LHC
partN0 50 100 150 200 250 300 350
AA
Rψ
J/
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
uncertaintycollSTAR N
STAR preliminary > 0 GeV/cψT,J/
p, |y| < 0.5-µ+µ→ψ = 200 GeV, J/NNsSTAR: Au+Au,
, |y| < 0.35-e+e→ψ = 200 GeV, J/NNsPHENIX: Au+Au, , |y| < 0.8-e+e→ψ = 2.76 TeV, J/NNsALICE: Pb+Pb,
03/31/2017 Rongrong Ma (BNL), Moriond 18
ALICE : PLB 734 (2014) 314 PHENIX : PRL 98 (2007) 232301 pT
> 0 GeV/c
• pT > 0 GeV/c: more suppressed at RHIC in central events à smaller regeneration contribution due to lower charm cross-section
CMS: JHEP 05 (2012) 063
• pT > 5 GeV/c: less suppressed at RHIC à smaller dissociation rate due to lower temperature
J/ψ RAA: RHIC vs. LHC pT
> 5 GeV/c
partN0 50 100 150 200 250 300 350
AA
Rψ
J/
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
uncertaintycollSTAR N
-µ+µ→ψJ/ > 5 GeV/c
T = 200 GeV, |y| < 0.5, pNNsSTAR: Au+Au,
> 6.5 GeV/cT
= 2.76 TeV, |y| < 2.4, pNNsCMS: Pb+Pb,
STAR preliminary
ϒ Suppression at RHIC
• ϒ(1S) is suppressed – Indication of more suppression with increasing centrality – Is direct ϒ(1S) suppressed?
03/31/2017 Rongrong Ma (BNL), Moriond 19
partN0 100 200 300 400
pA, A
AR
0
0.2
0.4
0.6
0.8
1
1.2
1.4 0-60%30-60% 10-30% 0-10%
(1S): Au+Au@200 GeV |y|<0.5ϒ(1S+2S+3S): p+Au@200 GeV |y|<0.5ϒ
uncertaintycollSTAR N
STAR Preliminary
ϒ(1S) RAA
ϒ Suppression at RHIC
• ϒ(1S) is suppressed – Indication of more suppression with increasing centrality – Is direct ϒ(1S) suppressed?
03/31/2017 Rongrong Ma (BNL), Moriond 20
partN0 100 200 300 400
pA, A
AR
0
0.2
0.4
0.6
0.8
1
1.2
1.4 0-60%30-60% 10-30% 0-10%
(1S): Au+Au@200 GeV |y|<0.5ϒ(1S+2S+3S): p+Au@200 GeV |y|<0.5ϒ
uncertaintycollSTAR N
STAR Preliminary
partN0 100 200 300 400
(1S)
ϒ(2
S+3S
)/ϒ
0
0.1
0.2
0.3
0.4
0.5
0.6 0-60%30-60% 10-30% 0-10%
STAR Au+Au@200 GeV |y|<0.5pp world-wide average
uncertaintycollSTAR N
STAR Preliminary
World-wide p+p: W. Zha, et. al, PRC 88 (2013) 067901
• Central: ϒ(2S+3S) is more suppressed à sequential melting
ϒ(1S) RAA ϒ(2S+3S)/ϒ(1S)
ϒ: RHIC vs. LHC
• ϒ(1S) suppression: similar at RHIC and LHC
03/31/2017 Rongrong Ma (BNL), Moriond 21
partN0 100 200 300 400
pA, A
AR
0
0.2
0.4
0.6
0.8
1
1.2
1.4 0-60%30-60% 10-30% 0-10%
(1S): STAR Au+Au@200 GeV |y|<0.5ϒ(1S): CMS [email protected] TeV |y|<2.4ϒ(1S+2S+3S): STAR p+Au@200 GeV |y|<0.5ϒ
uncertaintycollSTAR N
STAR Preliminary
CMS: arXiv:1611.01510 ϒ(1S) RAA
partN0 100 200 300 400
pA, A
AR
0
0.2
0.4
0.6
0.8
1
1.2
1.4 0-60%30-60% 10-30% 0-10%
(1S): STAR Au+Au@200 GeV |y|<0.5ϒ(1S): CMS [email protected] TeV |y|<2.4ϒ(1S+2S+3S): STAR p+Au@200 GeV |y|<0.5ϒ
uncertaintycollSTAR N
STAR Preliminary
ϒ: RHIC vs. LHC
• ϒ(1S) suppression: similar at RHIC and LHC
03/31/2017 Rongrong Ma (BNL), Moriond 22
CMS: arXiv:1611.01510
• Ralf model: seems consistent with ϒ(1S) suppression by including CNM and regeneration – However, under-predicts the ϒ(2S) suppression at the LHC
R. Rapp (QM2017) ϒ(1S) RAA
partN0 100 200 300 400
pA, A
AR
0
0.2
0.4
0.6
0.8
1
1.2
1.4 0-60%30-60% 10-30% 0-10%
(1S): STAR Au+Au@200 GeV |y|<0.5ϒ(1S): CMS [email protected] TeV |y|<2.4ϒ(1S+2S+3S): STAR p+Au@200 GeV |y|<0.5ϒ
uncertaintycollSTAR N
STAR Preliminary
ϒ: RHIC vs. LHC
• ϒ(1S) suppression: similar at RHIC and LHC
03/31/2017 Rongrong Ma (BNL), Moriond 23
CMS: arXiv:1611.01510
partN0 100 200 300 400
AA
R
0
0.2
0.4
0.6
0.8
1
1.2
1.4 0-60%30-60% 10-30% 0-10%
95% C. L.
(2S+3S): STAR Au+Au@200 GeV |y|<0.5ϒ(2S): CMS [email protected] TeV |y|<2.4ϒ(3S): CMS [email protected] TeV |y|<2.4ϒ
uncertaintycollSTAR NSTAR Preliminary
• ϒ(2S+3S): hint of less suppression at RHIC than at the LHC
ϒ(1S) RAA ϒ(2S+3S) RAA
Summary & Outlook
03/31/2017 Rongrong Ma (BNL), Moriond 24
• Upgrades of HFT and MTD greatly enhance STAR’s capabilities of measuring both open and hidden heavy flavor production.
Summary & Outlook
03/31/2017 Rongrong Ma (BNL), Moriond 25
• Upgrades of HFT and MTD greatly enhance STAR’s capabilities of measuring both open and hidden heavy flavor production.
• Open heavy flavor – Mass hierarchy of energy loss à strong interaction with medium – Collective behavior of charm quarks à suggests thermal equilibrium – Charm quarks seem to also participate in coalescence hadronization
Summary & Outlook
03/31/2017 Rongrong Ma (BNL), Moriond 26
• Upgrades of HFT and MTD greatly enhance STAR’s capabilities of measuring both open and hidden heavy flavor production.
• Open heavy flavor – Mass hierarchy of energy loss à strong interaction with medium – Collective behavior of charm quarks à suggests thermal equilibrium – Charm quarks seem to also participate in coalescence hadronization
• Quarkonium – Strong suppression of J/ψ at high-pT in central collisions à dissociation – ϒ(2S+3S) is more suppressed than ϒ(1S) in central collisions à sequential
melting – ϒ(1S) RAA: RHIC ≈ LHC. Model including CNM, dissociation, regeneration
seems consistent with data
Summary & Outlook
03/31/2017 Rongrong Ma (BNL), Moriond 27
• Upgrades of HFT and MTD greatly enhance STAR’s capabilities of measuring both open and hidden heavy flavor production.
• Open heavy flavor – Mass hierarchy of energy loss à strong interaction with medium – Collective behavior of charm quarks à suggests thermal equilibrium – Charm quarks seem to also participate in coalescence hadronization
• Quarkonium – Strong suppression of J/ψ at high-pT in central collisions à dissociation – ϒ(2S+3S) is more suppressed than ϒ(1S) in central collisions à sequential
melting – ϒ(1S) RAA: RHIC ≈ LHC. Model including CNM, dissociation, regeneration
seems consistent with data • Outlook: 2016 Au+Au data
– A factor of 2 (minimum-bias) and 5 (high-pT electrons) for HFT – Equivalent statistics for ϒ measurement
ϒ RAA vs. pT
• ϒ(1S): no obvious dependence on pT; similar to CMS
• ϒ(2S+3S): hint of less suppression at high pT
03/31/2017 Rongrong Ma (BNL), Moriond 29
ϒ(1S) ϒ(2S+3S)
(GeV/c)T
p0 2 4 6 8 10
AA
R
0
0.2
0.4
0.6
0.8
1
1.2STAR Au+Au@200 GeV (0-60%)
-µ+µ→ϒ(1S) |y|<0.5 ϒCMS [email protected] TeV (0-100%)
(1S) |y|<2.4 ϒ
STAR Preliminary
(GeV/c)T
p0 2 4 6 8 10
AA
R
0
0.2
0.4
0.6
0.8
1
1.2STAR Au+Au@200 GeV (0-60%)
-µ+µ→ϒ(2S+3S) |y|<0.5 ϒCMS [email protected] TeV (0-100%)
(2S) |y|<2.4ϒ
90% C. L.
STAR Preliminary